Densified wood including process for preparation
A wood substrate or member is included, having an increased density with respect to natural, untreated wood. The process includes drying the wood prior to application of heat and pressure, which are controlled to reduce or eliminate color change on a surface of the wood member where heat and pressure are applied.
1. A method for increasing the density of a wood member including:
(a) preheating a wood member by introducing the wood member to a temperature in a range of about 250° F. to about 500° F., wherein the preheating is for a time sufficient to reduce moisture content of the wood member to between 0 to about 2% 5% and to obtain a core temperature of the wood member of about 250° F. to about 500° F.;
(b) after reducing the moisture content of the wood member to between 0 to about 2% and obtaining the core temperature of the wood member of about 250° F. to about 500° F., applying pressure to the wood member for a single press cycle for a press time of about 30 seconds to about 10 minutes, wherein heat is applied during the applying of pressure to maintain the core temperature during the applying of pressure in a range of about 250° F. to about 500° F.; and
(c) providing a post-treatment conditioning of the wood member.
2. The method of claim 1 , further comprising:
cooling the wood member before the post-treatment conditioning.
3. The method of claim 1 , wherein the post-treatment conditioning includes the introduction of steam, humidity, heat or combinations thereof.
4. The method of claim 1 , wherein the moisture content of the wood member prior to preheating is about 0 to about 19%.
5. The method of claim 1 , wherein said pressure is about 500 psi to about 5,000 psi.
6. The method of claim 1 , wherein the applying of pressure is conducted with a heated platen press, a continuous press, a series of mills, or a combination thereof.
7. The method of claim 1 , further comprising reducing the moisture content of the wood member prior to preheating.
8. The method of claim 1 , wherein the wood member is a hardwood.
9. The method of claim 8 , wherein the hardwood is selected from the group including one or more of: red oak; white oak; hickory; walnut; aspen; basswood; maple; cherry; and, ash.
10. The method of claim 1 , wherein the wood member is a softwood.
11. The method of claim 10 , wherein the softwood is selected from the group including one or more of: poplar and pine.
12. The method of claim 1 , wherein the heat is applied during the applying of pressure to maintain the core temperature during the applying of pressure in the range of about 250° F. to about 400° F.